The molecular characteristics of poly(4-tert-butoxystyrene) (O) upon hydrolysis reaction were investigated. It is known that O can be converted into poly(4-hydroxystyrene) (H) through hydrolysis reaction using strong acid. In this study, a set of poly(4-tert-butoxystyrene-co-4-hydroxystyrene)s (O/H copolymers) having various conversion rates, fHs, were prepared. Hydrolysis reaction is found to occur uniformly by matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF MS) where the average fH obtained was consistent with that from 1H NMR though a certain distribution in the number of hydrolyzed units was conceived. Monomer sequence of O/H copolymers was determined by 13C NMR and the changes in triad concentration were obtained by spectra subtraction method. As a result, 13C NMR reveals that O and H are statistically distributed. To evaluate the effect of hydrolysis on microphase-separated structure, we observed the morphology of partially hydrolyzed poly(4-tert-butylstyrene-block- 4-tert-butoxystyrene) (BO) by transmission electron microscopy (TEM) and small-angle X-ray scattering (SAXS). Samples with fH from 0.21 to 0.67 form both lamellar (major component) and cylindrical (minor component) structures reflecting both the statistical manner of hydrolysis reaction and the possible localized distribution of H sequence.
All Science Journal Classification (ASJC) codes
- Organic Chemistry
- Polymers and Plastics
- Materials Chemistry